Abstract:
Nuclear magnetic resonance (NMR) techniques for probing sea ice cracks and imperfections and the use of this as a tool for wide ranging surveys of sea ice properties was investigated over several seasons. A probe is lowered into an angular cut made in the sea ice and measurements of brine diffusion are made. NMR uses the earth's magnetic field to obtain a sign from the liquid brine which is ... entrapped in the array included within the sea ice. With the application of suitable profiled magnetic field gradient, it is possible to measure the diffusion of the brine, both in a vertical and horizontal direction which has the potential to yield information about brine pocket anisotrophy and the degree to which brine diffusivity (and hence the thermal conductivity of the sea ice) is affected by convective instabilities. The design of the NMR device was changed and trialled. Brine diffusivity was measured in both vertical and horizontal directions at depths down to 1400 mm.